Hi Dave, You will probably want to convert your LIDAR point cloud to a DEM raster. You can do that easily in Q. It sounds like you may be looking for Topographic Prominence. You should look at the Wikipedia page for that to get a start. https://en.wikipedia.org/wiki/Topographic_prominence#Calculations_and_mathematics There is an open source project called WinProm, you can see the code on Github and it looks like there are windows exe files too.https://github.com/edwardearl/winprom
You can also use the r.geomorphon tool in GRASS and then extract summits and depressions. GRASS can be run from within QGIS.https://grass.osgeo.org/grass78/manuals/r.geomorphon.html There is likely a way to do it in python or R also, using one of the math or science packages, to find peaks and valleys in a 2d surface (Calculus). This is a well developed area of research, for example in biomedicine. ---------------------------------------------------------------------- Message: 1 Date: Thu, 2 Apr 2020 19:51:18 +0000 From: Dave Marshall <43carn...@gmail.com> To: qgis-user@lists.osgeo.org Subject: [Qgis-user] Working with LIDAR data in QGIS Message-ID: <CAOuYquPg8Yjj95g4yGmpKEVg06q53B-u=so58mjbonlr1r9...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hello, I am relatively new to QGIS but have been able to generate some useful images of LIDAR data with contours and shading. My need is to be able to identify hill summits and preferably cols as well and to extract the precise location and height of these positions. I'd like to know if it's possible to extract the height data for a specific point using QGIS. Thanks in advance for any help with this, Dave Marshall
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